Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species
The morphology, mixing state and hematite content of polluted mineral dust are not well accounted in the optical models and this leads to uncertainty in the radiative forcing estimation. In the present study, based on the morphological and mineralogical characterisation of polluted dust, the three-s...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Stockholm University Press
2012-05-01
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| Series: | Tellus: Series B, Chemical and Physical Meteorology |
| Subjects: | |
| Online Access: | http://www.tellusb.net/index.php/tellusb/article/view/18536/pdf_1 |
| _version_ | 1811252613976424448 |
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| author | S. K. Mishra S. N. Tripathi Shankar G. Aggarwal Anti Arola |
| author_facet | S. K. Mishra S. N. Tripathi Shankar G. Aggarwal Anti Arola |
| author_sort | S. K. Mishra |
| collection | DOAJ |
| description | The morphology, mixing state and hematite content of polluted mineral dust are not well accounted in the optical models and this leads to uncertainty in the radiative forcing estimation. In the present study, based on the morphological and mineralogical characterisation of polluted dust, the three-sphere, two-sphere and two-spheroid model shapes are considered. The optical properties of the above model shapes are computed using Discrete Dipole Approximation code. The single scattering albedo, ω0, was found to vary depending on hematite content (0–6%) and model shape. For the two-sphere BC-mineral dust system, hematite was found to be a dominating absorber compared to that of black carbon as the RBC/R dust decreases. The ω 0 of the polluted dust system is larger if polluted dust is considered as pure dust spheroid (with 4% hematite) while smaller value is observed for Q ext. Among all the systems, the ω 0 of BCBCD (two BC spheres attached to one dust sphere) system showed the maximum departure (40 and 35% for polluted dust with 0 and 6% hematite, respectively) from that of pure dust spheroid with 0 and 6% hematite. For the Asian region (pollution-prone zone), the modelled polluted dust optics will help to trace the optical and radiative properties of dust. |
| first_indexed | 2024-04-12T16:37:17Z |
| format | Article |
| id | doaj.art-154389a026234edd8303c68c98299d9f |
| institution | Directory Open Access Journal |
| issn | 0280-6509 1600-0889 |
| language | English |
| last_indexed | 2024-04-12T16:37:17Z |
| publishDate | 2012-05-01 |
| publisher | Stockholm University Press |
| record_format | Article |
| series | Tellus: Series B, Chemical and Physical Meteorology |
| spelling | doaj.art-154389a026234edd8303c68c98299d9f2022-12-22T03:24:55ZengStockholm University PressTellus: Series B, Chemical and Physical Meteorology0280-65091600-08892012-05-0164011810.3402/tellusb.v64i0.18536Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous speciesS. K. MishraS. N. TripathiShankar G. AggarwalAnti ArolaThe morphology, mixing state and hematite content of polluted mineral dust are not well accounted in the optical models and this leads to uncertainty in the radiative forcing estimation. In the present study, based on the morphological and mineralogical characterisation of polluted dust, the three-sphere, two-sphere and two-spheroid model shapes are considered. The optical properties of the above model shapes are computed using Discrete Dipole Approximation code. The single scattering albedo, ω0, was found to vary depending on hematite content (0–6%) and model shape. For the two-sphere BC-mineral dust system, hematite was found to be a dominating absorber compared to that of black carbon as the RBC/R dust decreases. The ω 0 of the polluted dust system is larger if polluted dust is considered as pure dust spheroid (with 4% hematite) while smaller value is observed for Q ext. Among all the systems, the ω 0 of BCBCD (two BC spheres attached to one dust sphere) system showed the maximum departure (40 and 35% for polluted dust with 0 and 6% hematite, respectively) from that of pure dust spheroid with 0 and 6% hematite. For the Asian region (pollution-prone zone), the modelled polluted dust optics will help to trace the optical and radiative properties of dust.http://www.tellusb.net/index.php/tellusb/article/view/18536/pdf_1mineral dusthematitesemi-external mixingmorphologyoptical propertiescarbonaceous particles |
| spellingShingle | S. K. Mishra S. N. Tripathi Shankar G. Aggarwal Anti Arola Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species Tellus: Series B, Chemical and Physical Meteorology mineral dust hematite semi-external mixing morphology optical properties carbonaceous particles |
| title | Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species |
| title_full | Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species |
| title_fullStr | Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species |
| title_full_unstemmed | Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species |
| title_short | Optical properties of accumulation mode, polluted mineral dust: effects of particle shape, hematite content and semi-external mixing with carbonaceous species |
| title_sort | optical properties of accumulation mode polluted mineral dust effects of particle shape hematite content and semi external mixing with carbonaceous species |
| topic | mineral dust hematite semi-external mixing morphology optical properties carbonaceous particles |
| url | http://www.tellusb.net/index.php/tellusb/article/view/18536/pdf_1 |
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